I think the awnser is probably B
The methods of the HUAC and the treatment of the Hollywood 10 reflect the Cold War beliefs of many Americans in that: D. People believed that communist propaganda was the main message in American film.
<h3>Who are communists?</h3>
Communists are people that believe that the resources of a nation should be collectively owned and distributed. This runs contrary to the American idea of Capitalism and this issue was paramount during the cold war.
So, the imprisonment of the screenwriters and movie directors above shows the belief at the time that communist propaganda was the main message in American film.
Learn more about communism here:
brainly.com/question/1092276
Heinrich Himmler implemented Hitler's Holocaust plan to uproot eastern Europeans and send German peasants to colonize their land. They were Nazis and Himmler was responsible for the Holocaust, and directed the mass killing of six million Jewish people, and many other ethnicities. He later committed suicide in the British custody.
Canals, Reservoirs, Dams
(I’m not 100% sure, but though they used flooding to their advantage it wasn’t a form of water control)
